Controlling device



Dec. 31, 1940.

w. A. SMITH, SR CONTROLLING DEVICE Filed Sept. 30, 1939 2 Sheets-Sheet lINVENTOR- Willz H IS ATTORNEY.

Dec. 31, 1940. w s n- 5 2,227,282

CONTROLLING DEVICE Filed Sept. 30, 1939 2 Sheets-Sheet 2 INVENTORmam/711A amiifi BY HI 5 ATTORNEY.

Patented Dec. 31 194) UNITED STATES CONTROLLING DEVICE William A. Smith,Sr., Athens, Pa., assignor to Ingersoll-Rand Company, Jersey City, N.J., a corporation of New Jersey Application September 30, 1939, SerialNo. 297,211

6 Claims.

This invention relates to rock drills, and more particularly to acontrolling device for the feeding mechanism of rock drills ofthe fluidactuated type.

One object of the invention is to effect the automatic release of thefeeding element from the motor whereby it is driven in the event ofundue resistance to rotation of the working implement actuated by therock drill.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawings accompanying this specification and in which similarreference numerals refer to similar parts,

Figure 1 is a longitudinal elevation, partly broken away, of a portionof a rock drillequipped with a controlling device constructed inaccordance with the practice of the invention,

Figure 2 is a transverse view taken through Figure l on the line 2-2looking in the direction indicated by the arrows,

Figure 3 is a transverse view taken through Figure 1 on the line 3-3,and

Figure 4 is a diagrammatic view, partly broken away, of the controllingdevice and a portion of the rock drill.

Referring more particularly to the drawings, 26 designates, in general,a drilling mechanism comprising a rock drill 2| and a shell 22 to guidethe rock drill with respect to thework.

The rock drill 2| comprises a cylinder 23 having a piston chamber 24 toaccommodate a hammer piston 25 reciprocable in the piston chamber 24 foractuating a drill steel (not shown). The pressure fluid used to actuatethe piston 25 is valved to the piston chamber 24 by suitable valvemechanism 26 arranged rearwardly of the piston chamber 24 and of whichonly the chest is shown, and seated on the rearward end of the valvemechanism 26 is a motor 21 serving the dual function of imparting rotarymovement to the drill steel and to move the rock drill 2| relatively tothe shell .22 for maintaining the drill steel in substantially thecorrect position with respect to the work.

The motor 21 is of the uni-directional, rotary vane type. It comprises acylinder 28 which may be keyed to the cylinder 23 in any suitable mannerand has a piston chamber 29 to accommodate a rotor 30 containingradially slidable vanes 3| against which pressure fluid acts forrotating the rotor. The rotor 30 is mounted upon and keyed to a shaft 32extending beyond the ends of the "cylinder 28 into the valve chest 26and into a cylinder extension 33 forming a closure for the rear end ofthe cylinder 23.

The end of the shaft 32 lying within the cylinder extension 33 carries apinion 34 that meshes with a gear 35 of a transmission shaft 36 jour- 5naled in the extension 33. The shaft 36 has a pinion 31 intermediate itsends to mesh with a gear 38 of a shaft 39 extending forwardly along therock drill cylinder to drive the chuck mechanism (not shown) Wherewiththe drill steel is slidably interlocked, in a well known manner.

The motion required for effecting feeding movement of the rock drillrelatively to the shell 22 is also transmitted by the shaft 36. Thisshaft is accordingly provided with a pinion 46, on its 5 rearward end,to mesh with a pair of gears 4i and 42 of which the gear 42 is aninternal gear and encircles the gear 4|. The gears 4| and 42,respectively, constitute portions of driving members 43 and 44 arrangedin a recess 45 in the opposed ends of the cylinder extension 33 and aback head 46 forming the rearmost casing part of the rock drill.

The gear 4| has an integral sleeve 41 which is 25 rotatable upon astationary shaft 48 seated in the extension 33 and the back head 46. Therearward end of the sleeve 41 forms a seat for the driving member 43which is clamped against a shoulder 49 on the sleeve 41 by a nut 55. Thedriving member 44 may, as shown, form an integral part of the gear 42,and between said driving member and the gear 42 is an anti-frictionbearing 5| the inner race of which is seated directly on the sleeve 41.35

In the opposed surfaces of the driving members 43 and 44 are pistonchambers 52 and 53, respectively, to receive pistons 54 and 55 whichhave a sufficiently loose fit in the piston chambers to permit of amoderate degree of leakage 40 of fluid medium across their peripheriesinto the recess 45. The pistons are carried by a sprocket wheel 56arranged between the driving members and the outermost ends of thepistons 54 and 55 constitute friction surfaces 51 adapted to engagefriction discs 58 arranged in the bottoms of the piston chambers 52 and53.

The sprocket wheel 56 is rotatable on and slidable longitudinally of thesleeve 41 and engages a chain 59 which is trained over sprocket teeth 60carried by a feed nut 6i journaled in a lug 62 on the cylinder extension33. The feed nut is freely rotatable in the lug 62 and is in threadedengagement with a feed screw 63' extending therethrough andlongitudinally of the shell 22 supports the feed screw.

Normally the feed screw 63 remains stationary and may be held thus by alatch 64 having a detent 65 to engage notches 66 in a flange 61 near therear end of the feed screw. The latch is maintained in loclnngengagement with the feed screw by a spring 60, and on the rearwardextremity of the feed screw is the usual crank 69 whereby the feed screwmay be manually rotated, if desired.

In order that the sprocket wheel may be conveniently actuated into andheld in frictional engagement with the friction discs 58 for rotatingthe feed nut 6! in one direction or the other, depending upon thedirection in which it is desired to actuate the rock drill relatively tothe shell, the ends of the pistons 54 and 55 adjacent the friction discs58 serve as actuating surfaces I and 'II, respectively, against whichpressure fluid acts for shifting the sprocket wheel relatively to thefriction discs. The pressure fluid employed for thus shifting thesprocket wheel 56 is conveyed to the piston chambers 52 and 53 by inletpassages I2 and 13. The passages I2 and I3 lead through the shaft 48 andthe cylinder extension 33 to a valve chamber I4, in the extension 33,containing a throttle valve I of the rotary type for controlling thepassages I2 and 13.

Within the throttle valve is a bore I6 into which pressure fluid mayflow, in the extreme positions of the throttle valve, through ports 11and I8 radiating from the bore I6 and adapted to register with a passageI9 leading to a supply chamber 80 in the extension 33. The throttlevalve I5 is, moreover, provided with two sets of ports of which theports of a set are angularly disposed with respect to each other. Eachof these sets of ports serves to communicate the bore I6 with thepassages leading to the piston chambers in the driving members. Thoseassociated with the passage I2 are designated 8| and 02 and the portsintended to register with the passage I3 are designated 83 and 84.

In the'periphery of the throttle valve I5 and in the transverse planesof the points of communication of the passages I2 and 73 with the valvechamber I4 are partly annular grooves 85 and 86 to afford communicationwith exhaust ports 81 for opening the piston chambers 52 and 53 to theatmosphere.

The supply chamber 80 is in constant communication with a source ofpressure fluid supply through a conduit 88 connected to the cylinderextension 33, and adjacent the supply chamber 80 is a second throttlevalve 89 for controlling the admission of pressure fluid to the motor 21and the valve mechanism 26. The throttle valve 89 is preferably of thesame type as the throttle valve I5 and has a bore 90 to convey pressurefluid to a port 9!, in the wall of the throttle valve, registering witha passage 92 leading to the valve mechanism 26. The throttle valve 89has a second port 93 to register with a passage 94 leading through theextension 33 and the motor cylinder 28 to the piston chamber 29.

Under certain conditions of operation, the pressure fluid used forshifting the sprocket wheel 56 into engagement with the friction discs58 is controlled by manipulation of the throttle valve I5, as, forexample, when first starting a drill hole or when the force operating toretract the drill steel from the drill hole meets little or noresistance from the cuttings in the drill hole.

which During normal drilling, however, the supply of pressure fluid tothe piston chambers 52 and 53 is preferably controlled automatically sothat if resistance to the rotation of the drill steel in the drill holebecomes excessive, the driving connection between the motor and thefeeding mechanism may be automatically disconnected in order that thepower of the motor 21 may be applied exclusively to the rotationmechanism of the rock drill for freeing the drill steel. In furtheranceof this end the rock drill is provided with valve mechanism designatedin its entirety by 95 that acts responsively to fluctuations in thepressure fluid flowing to the motor 2'! for valving pressure fluid tothe piston chambers 52 and 53.

The valve mechanism 95 is located in the cylinder extension 33. Itcomprises a bushing 96 the interior of which constitutes a valve chamber97 to accommodate a reciprocatory valve 98 having a pair of heads 99 andI00 connected by a reduced stem IOI.

In the forward end of the bushing 96 is a bridge I02 which forms a seatfor an extension I03 at the forward end of the head I00 of the valve.The rearward end of the valve seats against a spring I04 which isinterposed between the valve and the end surface of the valve chamber 91to retain the extension I03 against the bridge I02. Preferably, theportion of the valve chamber 91 containing the spring I04 iscommunicated with the recess 45 by a port I05 in the extension 33 andthe recess 45 is, in turn, open to the atmosphere through a port I06 inthe back head 46.

The pressure fluid supplied to the motor 2! passes through the valvechamber 91 across a pressure surface I9 on the front end of the headI00. The bushing 96 is accordingly provided with a port I0'I which is solocated with respect to the front end of the head I00 of the valve 98that normally only a portion of the port will be uncovered by the headI00 which controls said port.

The bushing 96 is provided with another port I08 located immediatelyrearwardly of the head I00 whereby it is controlled and said port I08opens into the branch of the passage 94 leading from the valve mechanism95 to the throttle valve 89 to convey pressure fluid into the valvechamber 91 between the heads I00 and 99. The pressure fluid thusadmitted into the intermediate portion of the valve chamber 9! passestherefrom through ports I09 opening into a supply passage I I0 leadingto the throttle valve chamber 14, and in the throttle valve I5 are apair of relatively angularly disposed ports Iii and H2 to affordcommunication between the supply passage H0 and the bore I6 in differentpositions of the throttle valve I5.

As is customary, the rock drill is provided with a water tube II3extending coaxially through the rock drill for supplying cleansing fluidto the drill hole to flush the cuttings therefrom. The water tube H3 maybe of any Well known type and is secured in position by a plug II4threaded into the rearmost end of the back head 48.

As a first step in the operation of the device, and assuming that it isintended to move the rock drill toward the work to actuate the drillsteel thereinto, the throttle valve 89 is opened to admit pressure fluidto the passages 92 and 94 and thus to the valve mechanism 26 and themotor 21. The valve mechanism 26 will then operate to distributepressure fluid to the ends of the piston chamber 24 for actuating thepiston 25 against the drill steel. At the same time the motor 21 is setin operation and its movement is transmitted through the shaft 36 to theshaft "39 for rotating the drill steel to new positions between theblows of the hammerpiston.

Simultaneously with or immediately following the starting of, the motor21 and the percussive element of thedrill the valve I is rotated to theposition shown in Figure 4 in which the port 'I'I registers with thepassage I9 and the port 83 reg- 'isters with the passage I3. Pressurefluid then .flows from the supply chamber 80 to the piston chamberE'sagainst the actuating surface 51 and shifts the sprocket wheel 55into frictional engagement with the adjacent friction disc 58 carried bythe driving member 43.. a

The sprocket wheel 56 will then rotate with the driving member 43 andits. rotary movementv is transmitted through the chain 59 to the feednut JIiI which will then be rotated relatively to the feed screw sothatthe rock drill 2| will be advanced along the shell 22 toward the work.in accordance with the penetration of the drill steel thereinto. In thisway the percussive element of the rock drill will be constantlymaintained in the correct operative relationship with the drill steel.

The throttle valve 75 remains in the position described until the drillhole has been started and is then shifted to a position in which theport II is moved out of registry with the passage I9 and the port I I Iregisters with the supply passage I I0 and the port 84 registers withthe passage I3. Pressure fluid then flows from the valve chamber Blthrough the supply passage II!) and associated passages into the pistonchamber 53 for holding the sprocket wheel in engagement with the drivingmember 43.

In the new position of the throttle valve 15 the supply of pressurefluid will be controlled only by the valve 53, the pressure surface I9of which is constantly exposed to the value of the pressure fluidflowing to the motor 21. Thus, if during the ensuing operation of thedrilling mechanism, the resistance to the rotation of the motor'increases, as when a collar of detritus on the drill 'steel tends tobind it in the drill hole, the pressure acting against the pressuresurface I9 will closely the flow of pressure fluid into the valvechamber 9'! By reason of this throttling action of. the valve t3 thesupply of pressure fluid to the piston chamber 53 will be diminished orentirely out off and owing to the slight clearance between the peripheryof the piston 55 and the wall of the piston chamber 53 the pressurefluid will leak from the piston chamber 53 and release the sprocketwheel 55 from the driving member 43.

By thus releasing the sprocket wheel the feeding mechanism will bedisconnected from the motor and the power of the latter will then beapplied only to the rotation mechanism for turningthe drill steel. Afterthe drill steel is again free to rotate the speed of the motor 21 willincrease. Consequently, there will then be a reduction in the pressureforwardly of the pressure surface I9 and the spring I04 will shift thevalve forters with the passage I2.

wardly to restrict the flow area of port I01 and to uncover theportfI08. A full supply of pressure fluid will thereby be admitted tothe piston chamber 53 andthe sprocket wheel will again be actuated intofrictional engagement with the driving member 43.

After the drill steel has penetrated the work to the limit of its extentthe throttle valve 15 is rotated, toa new position in which the port II2 registers with the passage I I0 and the port 82 regis- Pressure fluidwill then flow from the valve chamber 91 through the supply passage IIt, the bore It of the throttle valve and through the passage I2 intothe piston chamber 52 and pressthe sprocket wheel 56 into engagementwith the friction disc 58 carried by the driving: member 434. Thesprocket wheel and the associated elements will then be driven in adirection to cause retractive movement of the rock drill along theshe1l22, and during such movement of the rock drill the valve 98 willoperate in the manner previously described to eifect the release and thereengagement of the sprocket wheel with the driver 44 wheneverabnormalitiesin the drill hole hinder the rotative movement of the drillsteel,

In the event that the rock being drilled has little or no tendency tocreate a condition that might necessitate the breaking of the drivinconnection between the sprocket wheel and the driving element during theretractive movement of the rock drill the throttle valve I5 may beplaced in a position in which the port I8 is in registry with thepassage 19. In this positionthe throttle valve 15 will blank off thesupply passage I III and the port 8| will be in registry with thepassage I2. Pressure fluid may then flow directly from the supplychamber 80 through these channels into the piston chamber 52 for holdingthe sprocket wheel 56 in engagement with the driver 44.

In practice, the present invention has been found to be a highlydesirable device for automatically relieving the motor 21 whenever theload thereon becomes excessive. vantage in rock drills of the characterdescribed for the reason that it eliminates the necessity of constantattention and frequent manipulation of the various controlling elementsof the rock drill to maintain the drill steel free in the drill hole.

I claim:

1. A controlling device, comprising a casing, a

- fluid actuated motor, means driven by the motor,

fluid actuated clutch means to form a connection between the motor andthe first mentioned means, a valve to control the flow of pressure fluidto the clutch means, and a pressure surface on the valve subjected tothe fluctuations in the pressure of the fluid flowing to the motor foractuating said valve.

2. A controlling device, comprising a casing, a plurality of pressurefluid actuated devices in the casing, a passage for constantly conveyingpressure fluid to one of the devices, a channel for conveying pressurefluid to another device, a valve to control the flow of pressure fluidthrough the channel, a pressure surface on the valve constantlysubjected to the fluctuations in the pressure of the fluid in thepassage for actuating the valve to throttle the channel, and means forselectively communicating one of the devices with the channel and with asource of pressure fluid supply.

3. A controlling device, comprising a casing having a pressure fluidsupply chamber, a driven member, a fluid actuated motor for driving thedriven member, a clutch to form a connection-between the motor and thedriven member and hav- This is of great ad- I ing aniactuating surface,a valve acting responsively to the fluctuations in the pressure of thefluid flowing to the motor for controlling the flow of pressure fluid tothe actuating surface, and

-means for selectively communicating the actuating surface with thesupply chamber and with the valve.

4. A controlling device, comprising a casing, a

driven member, a fluid actuated motor for driving. the driven member, aclutch to form a connection between the motor and the driven member andhaving opposed actuating surfaces, a supply chanhel in the casing, avalve acting responsively to the fluctuations in the pressure of thefluid flowing to the motor for valving pressure fluid to the supplychannel, and means for selectively communicating the actuating surfaceswith the supply channel.

5. A controlling device, comprising a casing hav- :ing a pressure fluidsupply chamber, a driven member, a fluid actuated motor for driving thedriven the fluctuations in the pressure of the fluid flowing to themotor for valving pressure fluid to the supply channel, and a manuallyoperable valve for selectively communicating the actuating surfaces withthe supply chamber and with the supply channel.

6, Acontrolling device, comprising a casing having a pressure fluidsupply chamber, a driven member, a fluid actuated motor for driving saidmember, a clutch to form a connection between the motor and the drivenmember and having opposed actuating surfaces, a supply channel in thecasing, a spring-pressed valve acting responsively to the fluctuationsin the pressure of the fluid flowing to the motor for valving pressurefluid to the supply channel, and a throttle valve movable to differentpositions for cutting off communication between the supply channel andthe actuating surfaces and tosimultaneously communicate the actuatingsurfaces selectively with the supply chamber and said throttle valvebeing movable to other positions to selectively communicate theactuating surfaces with the supply channel.

WILLIAM A. SMITH, SR.

